code: def test_dotprint_depth():
      text = dotprint(3 * x + 2, depth=1)
      assert dotnode(3 * x + 2) in text
      assert dotnode(x) not in text
      text = dotprint(3 * x + 2)
      assert "depth" not in text
  
file_path: sympy/sympy/printing/tests/test_dot.py
imports: from sympy.printing.dot import purestr, styleof, attrprint, dotnode, dotedges, dotprint
  from sympy.core.basic import Basic
  from sympy.core.expr import Expr
  from sympy.core.numbers import Float, Integer
  from sympy.core.singleton import S
  from sympy.core.symbol import Symbol, symbols
  from sympy.printing.repr import srepr
  from sympy.abc import x
label_desc: Use image node_id 7 for calling a global function with example usage: test_dotprint_depth() without return types